The majority of biological fluid expression devices on the market today typically include some combination of the following parts: a breastshield assembly, collection bottles and/or bags, vacuum tubing, a high volume vacuum pump head, a direct drive motor, a battery pack, a power supply jack, and a controller.
Breastshield assemblies typically comprise a funnel shaped rigid outer shell, sometimes called a breastcup, and a tubular conduit structure sometimes referred to as a nipple tube. The funnel shaped breastcup has an area formed to receive a breast and nipple. While the majority of current pumps on the market today have rigid breastcups, the inclusion of a soft liner is sometimes allowed in an attempt to aid in sizing, comfort and fluid expression.
The nipple tube is typically made of plastic and/or silicone, but in some cases other materials are allowed for, to connect the breastcup to the container receptacle. The nipple tunnel is typically shaped to receive the nipple without collapsing, and often results in substantial movement and stretching of the nipple during expression. This tunnel is often used to allow an entry point for applying vacuum to express fluids.
On the opposite end of the nipple tube typically lies a receptacle of some sort. Often times the nipple tube terminates in a threaded fitting to allow the attachment of a plastic or glass bottle. In addition, polyethylene fluid storage bags, or bags of a variety of materials, have been used here to allow pumping into bags for freezer storage.
The entire assembly is pressurized with a negative pressure vacuum, forming a seal between the breast and the breastshield. When turned on, the vacuum begins to generate a cyclic pressure gradient using a diaphragm, piston, or bellows structure that typically vents to atmospheric pressure on the completion of each stroke cycle. In some instances, the diaphragm, bellows, or piston structure is manipulated using a linear actuation mechanism. This mechanism can be a rotary electric motor, a servomotor, or some other electromechanical system that moves an actuator arm through a reciprocating linear motion for the instroke and outstroke to generate the pressure waveform. This allows alternating positive and negative pressure to be introduced into the nipple tunnel for each stroke cycle. The duty cycle of each stroke is typically intended to mimic the suck-release profile of the suckling infant, with operating profiles with duty cycles in the one-half to two-thirds range targeted. Pumps typically target a frequency of 45-60 Hz again in an attempt to mimic a live suckling infant.
The negative pressure is transmitted from the vacuum to the nipple tunnel via the vacuum tubing, creating a pressurized chamber comprised of the breastcup, nipple tunnel, and the receptacle. In some devices gravity causes fluid to flow from the breast cup into the collection bottle, while other devices include valves to separate the receptacle during negative pressure generation to allow milk expression from the nipple into the nipple tunnel. Subsequently, the valve is opened and the system is vented to atmospheric pressure to allow fluid movement from the nipple tunnel into the receptacle.
Most of the commercially available pumps on the market today have characteristics that make them operate less efficiently than a nursing baby and with a higher degree of discomfort. The rigidity of the breastcup structures affects efficiency in that the funnel and nipple tube are not collapsible and therefore operate at large dead air volumes, depending on where the vacuum is plumbed into the assembly and where the valves are positioned, the amount of dead air volume that the pump must affect can vary. When dead air volume is not minimized, additional pressure is required to express liquid from the breast. This design is present in the majority of breast pumps on the market, and results in systems that generate maximum negative pressures between −200 and −500 mm Hg.
This increase in vacuum pressure also results in greater discomfort for the user. The nipple and surrounding tissue is pulled and stretched more dramatically within the nipple tunnel. Research has shown that movement of the nipple within the infant's mouth is on the order of 2 mm. This much greater movement seen in current nipple tube design increases discomfort and might constrict the terminal ends of the lactiferous ducts, thereby impeding fluid flow. Moreover, the excess breast tissue engaged by the large, rigid funnel of the breastcup applies the greater pressure to more sensitive anatomy.
Similarly, the current devices do not offer any method of quantifying certain environmental and biomechanical data regarding pumping biomechanics and efficiency to assist nursing mothers, or lactation consultants, in better evaluating and programming expression devices. Variables of interest could include, but are not limited to, fluid volume per minute, temperature of fluid, number of let-downs, pressure within devices, cycle parameters, duty cycle times, protein content, fat content, and overall time of usage. Knowledge of these variables is absent in current designs, and if included, could allow users to implement more efficient cycling programs, timing schedules to generate more efficient fluid expression and have a better understanding of the overall milk production and quality expressed via the device. In addition, automated feedback algorithms could be incorporated to use this data to automatically adjust cycle parameters during a session to increase efficiency. For example, current pumps on the market transition between nutritive and non-nutritive sucking cycle based entirely on previously programmed timers, or on user input. However, this assumes that all infants transition from non-nutritive to nutritive at the same time, and only once per sucking cycle, which we know to be inaccurate. Therefore, an automated transition between non-nutritive and nutritive suckling waveforms based on quantification of pressure and fluid flow within the system would allow multiple transitions during an expression session that would not require user input, and would improve expression efficiency. Further, many pumps include a controller system having a keypad or dial for user input. The controller offers the user the ability to program the lactation cycles by choosing various settings typically focusing on vacuum magnitude and cycle frequency. However, there is currently no pump available to consumers that is capable of sensing various internal fluid expression variables and modulating device settings automatically to optimize expression.
Finally, current pumps do not allow for mobile/smartphone control of devices, wireless connectivity between tablet and/or smartphones and devices, wireless cloud syncing and online device analysis, or comparative analysis and social networking with regards to device usage for users. The ability to wirelessly, and automatically upload environmental data to an online portal for personal analysis, as well as comparative analysis with the device community, is one that would assist many nursing mothers in improving pumping efficiency. This capability has not, to the inventors' knowledge, been included in any previous device.
The multitude of differences between the anatomy and biomechanics of a suckling infant and the structure and mechanics of current pumping devices result in lower efficiency, increased discomfort, decreased discretion, and bulky design. These problems combined with the lack of automation and updated connectivity to web/mobile devices leave room for innovation and increases in efficiency. Embodiments of the present invention aim in some aspects to solve these problems by implementing a biomimetic design of a fluid expression device to be used in both humans, as well as other mammals, combined with the inclusion of environmental sensors and web/mobile connectivity to control, automate, and analyze device and user function and biomechanics.